| <!-- |
| Licensed to the Apache Software Foundation (ASF) under one |
| or more contributor license agreements. See the NOTICE file |
| distributed with this work for additional information |
| regarding copyright ownership. The ASF licenses this file |
| to you under the Apache License, Version 2.0 (the |
| "License"); you may not use this file except in compliance |
| with the License. You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, |
| software distributed under the License is distributed on an |
| "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| KIND, either express or implied. See the License for the |
| specific language governing permissions and limitations |
| under the License. |
| --> |
| |
| # ST_FrechetDistance |
| |
| Introduction: Computes and returns discrete [Frechet Distance](https://en.wikipedia.org/wiki/Fr%C3%A9chet_distance) between the given two geometries, |
| based on [Computing Discrete Frechet Distance](http://www.kr.tuwien.ac.at/staff/eiter/et-archive/files/cdtr9464.pdf) |
| |
| If any of the geometries is empty, returns 0.0 |
| |
|  |
| |
| Format: `ST_FrechetDistance(g1: Geometry, g2: Geometry)` |
| |
| Return type: `Double` |
| |
| Since: `v1.5.0` |
| |
| SQL Example |
| |
| ```sql |
| SELECT ST_FrechetDistance(ST_GeomFromWKT('POINT (0 1)'), ST_GeomFromWKT('LINESTRING (0 0, 1 0, 2 0, 3 0, 4 0, 5 0)')) |
| ``` |
| |
| Output: |
| |
| ``` |
| 5.0990195135927845 |
| ``` |
